In some vehicle systems, ambient air is admitted into the system at a valve. If the valve is submerged when the valve is opened, water can enter the vehicle system. In many vehicle systems, water intrusion can cause damage either immediately, or over a course of time.
One example of a vehicle system that admits ambient air using a valve is an evaporative emissions control system that can be incorporated in vehicles having an internal combustion engine. The evaporative emissions control system of a vehicle is designed to prevent the release of fuel vapors into the atmosphere from the fuel storage and fuel delivery systems of the vehicle. In these systems, fuel vapors can be vented to a canister that contains an adsorbent material. One example of an adsorbent material that is used for this purpose is activated carbon.
During operation of the evaporative emissions system, fuel vapors that enter the canister are adsorbed by the activated carbon. Periodically, the fuel vapors are purged from the canister, and delivered to the engine where they are burned. In order to purge the fuel vapors from the canister, the fuel vapors are pumped under pressure from the canister to the engine. Because the evaporative emissions system is otherwise sealed, ambient air must be admitted to allow the fuel vapors to be purged from the adsorbent material and pumped to the engine. Thus, an ambient air inlet valve is opened to allow admission of ambient air when the fuel vapors are purged.
In some systems, ambient air intake components are protected by a shroud or cover. While these types of structures are effective in preventing intrusion of splashing water, they are not effective in preventing water intrusion when the ambient air intake components are submerged. In some systems, ambient air intake components are located in areas of the vehicle where they are less likely to become submerged. Doing so, however, is not always feasible.